A stereoselective synthesis of a pyranonaphthoquinone derivative found in aromatic polyketide-derived aphid pigments is reported herein. This approach features the anionic [4+2]-annulation of phthalides with a carbohydrate-derived optically active enone. Additional synthetic steps provide access to the monomer fragment of uroleuconaphins and viridaphins. The optimization for a facile preparation of phthalides bearing sulfonyl or cyano groups are also studied.
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